Card-shaped electronic apparatus

ABSTRACT

A PC card has a plastic frame provided along the periphery of a substrate. Metal plates, such as stainless steel plates and the like, cover both surfaces of the substrate and are attached to the plastic frame. External surfaces of the metal plates located in an area on the opposite side of a connector and which are touched by a person&#39;s hand are covered by an insulation tape, so that, even if a person charged with static electricity touches the PC card when the PC card is inserted or withdrawn from an external apparatus such as a personal computer (PC), the static electricity (charge) of the person does not flow into the external apparatus. Thus, malfunctions or erroneous operations of the external apparatus do not occur.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates to card-shaped electronic apparatuses, and moreparticularly, to contact type card-shaped electronic apparatuses thatuse a metal plate as its outer casing, including PC cards, such, as forexample, IC memory cards, I/O cards and the like.

2. Description of Related Art

In recent years, facsimile modem expansion boards for communicating withan external apparatus such as a personal computer (hereinafter referredto as PC), hard discs for expansion, and the like have been reduced to acard size, and made available as PC cards, in addition to the alreadyexisting card-shaped electronic apparatuses, such as, for example, ICmemory cards. These card-shaped electronic apparatuses use a metal platesuch as a stainless steel plate (hereinafter referred to as SUS) as anouter casing to increase the rigidity of the card-shaped electronicapparatus, to provide electrostatic resistance and to eliminate noiseproblems. Hereafter, a PC card will be described as an example of acard-shaped electronic apparatus.

FIG. 13 is an exploded view of a conventional PC card, and FIG. 14 is across-sectional view thereof. The PC card according to this example isone in which a conventional PC expansion board or an accessory isimplemented in a card-shaped apparatus. In the interior thereof, aninput/output integrated circuit (hereinafter referred to as aninput/output IC) 5, a semiconductor memory 6 and the like are mounted ona substrate 4. The PC card uses metal plates 2 as upper and lower outercasings for the card, as described above, in order to improve itstransportability, handling capability and reliability. The metal plates2 are fixed to a plastic frame 8 by a fixing means such as adhesive. Inorder to prevent unnecessary radiation, the upper and lower metal plates2 are further connected to ground line (hereinafter referred to as GND)of the substrate 4 through a conductive spring 3, as shown in FIG. 14.The PC card is equipped with a connector 1 for mounting on a PCapparatus.

Further, in order to facilitate the inserting and withdrawing of thecard, there have been cards in which independent slip-stoppers areattached to the metal plates 2, or slip-stopping grooves are provided onthe plastic case 8 in the side sections of the card-shaped electronicapparatus.

Some of the conventional PC cards are provided with an electrostaticcountermeasure that is effective upon mounting on a PC. On the otherhand, some of the cards are not provided with such a countermeasure dueto the limitations imposed by factors such as the space and cost of thecard, and the structure of a PC, i.e., the PC's receiving apparatus. Inparticular, even though a conventional electrostatic countermeasure maybe provided with a card, the countermeasure in the card alone may not besufficient, and a PC apparatus may be required to include acountermeasure according to the structure of the electrostaticcountermeasure implemented in the card. Also, an electrostaticcountermeasure may, in some cases, be implemented in a PC alone. Forexample, a lid is provided at the PC card insertion opening, and a pieceof metal is provided adjacent to the lid so that static electricity isled out to the frame GND of the PC through the piece of metal when thelid is opened and closed. However, although a lid may be provided at acard insertion opening of a relatively large PC, it is difficult toprovide such a structure in the latest PCs, such as, for example,notebook type PCs because of their size, depth and thickness.

Furthermore, PC cards are not provided with an electrostaticcountermeasure while they are inserted in a PC. As a result, when aperson charged with static electricity touches the card that is insertedin the PC, the charge (static electricity) of the person flows throughthe metal plates, the conductive spring and the GND within the card tothe PC apparatus. As a result, this could become one of the situationsthat triggers malfunctions, such as, for example, erroneous operationand halt of the PC.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide acard-shaped electronic apparatus that is electrostatic-resistant and iscapable of securely preventing discharge of static electricity by thecard alone.

Also, it is an object of the present invention to provide a highlyreliable card-shaped electronic apparatus which does not triggermalfunctions, such as, erroneous operation and halt of a PC and otherapparatuses when connected thereto.

Furthermore, it is an object of the present invention to realize, in acard-shaped electronic apparatus, a structure which facilitates itsoperation when the card is inserted for mounting or withdrawn fordismounting.

The invention has been made in order to solve the above-describedproblems, and its content will be described below.

A card-shaped electronic apparatus in accordance with the inventioncomprises a substrate on which electronic devices are mounted, aterminal that is disposed on one side of the substrate and that isbrought into contact with a data transmission and reception section ofan external apparatus main body for electrical connection, a frame thatis positioned at the periphery of the substrate, a metal member that isconnected to the frame and covers the substrate at least at the side ofthe terminal to define an outer casing section, and an insulation memberthat is connected to the frame at an opposite side with respect to theside of the terminal of the frame. By providing such a structure, theouter casing is formed from an insulation member at the location on theopposite side of the location where the terminal is provided, so that anarea of the insulation member is held for mounting or removing the card.Accordingly, for example, even when a person charged with staticelectricity inserts or withdraws the card, the static electricity is notdischarged to the apparatus side, and as a result, malfunctions of theapparatus mounted therewith can be prevented. In addition, since theterminal side is covered by the metal member, radiation is restricted tothereby eliminate noise problems.

The metal member covers both sides of the substrate, and furtherincludes a conductor member that electrically connects the metal memberand the substrate. In other words, the metal member is connected to GNDof the substrate. As a result, problems caused by external noise and thelike can be securely prevented.

Furthermore, the insulation member is disposed at least at a locationthat protrudes from the external apparatus body when mounted on theexternal apparatus. By this, the area that is covered by the metalmember increases. Accordingly, the rigidity of the card is readilymaintained, and even when a person charged with static electricitytouches the card that is inserted in the external apparatus, the staticelectricity is not discharged to the external apparatus side since theportion of the outer casing that protrudes from the external apparatusbody is in the insulation condition, and therefore malfunctions of theexternal apparatus are prevented.

Also, the insulation member and the frame may be integrally formed, themetal member and the insulation member may be integrally formed, and themetal member, the insulation member and the frame may be integrallyformed. By providing such structures, the number of parts andmanufacturing steps can be reduced, and the cost can be reduced.

Also, the insulation member may be formed to be externally protruded andto have a U-shape cross-section. By forming the insulation member in aU-shape, the thickness of the insulation member whose rigidity is lowercompared with the metal can be increased to increase the rigidity(strength) of the insulation member. A space for mounting electronicdevices such as semiconductor memories and the like can also be providedin an area that is covered by the insulation member of the substrate,and therefore a large substrate can be used. Also, since the thicknessbecomes greater by forming it in a U-shape, the operability of the cardupon its insertion and withdrawal is improved.

Also, a deform prevention section in a protruded shape may be formed inthe interior of the insulation member. By providing the deformprevention section, the protruded deform prevention section contacts thesubstrate or the insulation member on the opposite side so that theinsulation member is prevented from being deformed when the card isgripped and held. As a result, the thickness of the insulation membercan be reduced. In particular, the deform prevention members formed onthe respective insulation members which are disposed on both surfaces ofthe substrate may be made engageable with each other, so that theinsulation members are prevented from being deformed, and mutualpositioning thereof is readily performed.

Also, the metal member may be disposed to cover the entire surface ofthe substrate, and the insulation member may be disposed to cover theexternal surface of the metal member. The insulation member is disposedto cover the metal member which has a certain rigidity, so that theinsulation member can be selected from a wider range of materials. Theinsulation member that covers the metal member can be formed into asheet. When the insulation member is formed into a sheet, the insulationmember can be substantially readily disposed at the external surface ofthe metal member.

Preferably, plastic material is used for the insulation member. By usinga plastic material, a high insulation function is obtained, alight-weight member can be readily formed in any desired shape, and itcan be formed into a sheet.

Also, in any one of the above-described structures, the insulationmember is characterized in having a slip-stopper provided therewith. Byproviding such a structure, the operability of the card upon insertionand extraction of the card to a mounting body is improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of a first embodiment of theinvention;

FIG. 2 shows a cross-sectional view of a second embodiment of theinvention;

FIG. 3 shows an example of a variation of a plastic plate in accordancewith the invention;

FIG. 4 shows a perspective view of a plastic frame in accordance withanother embodiment of the invention;

FIG. 5 shows a cross-sectional view of a third embodiment of theinvention;

FIG. 6 shows a cross-sectional view of a variation of the thirdembodiment of the invention;

FIG. 7 shows an exploded perspective view of the main portion of afourth embodiment of the invention;

FIG. 8 shows a cross-sectional view of a fifth embodiment of theinvention;

FIG. 9 shows an exploded perspective view of a sixth embodiment of theinvention;

FIG. 10 shows a cross-sectional view of a seventh embodiment of theinvention;

FIG. 11 shows a perspective view of an eighth embodiment of theinvention;

FIG. 12 shows a cross-sectional view of the eighth embodiment of theinvention;

FIG. 13 shows an exploded view of a conventional PC card; and

FIG. 14 shows a cross-sectional view of a conventional PC card.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereafter, embodiments of the invention will be described with referenceto the drawings.

A card-shaped electronic apparatus includes any one of contact typecard-shaped electronic apparatuses that are operable by electricallyconnecting to a data transmission/reception section, such as, forexample, a connector that is present at the side of an externalapparatus.

The description of the invention will be made with reference to what isgenerally known as a PC card as an example of the card-shaped electronicapparatus. PC cards include I/O cards, such as, for example, fax/modemcards for communication with apparatuses external to the PCs,card-shaped hard discs for expansion, in addition to the alreadyexisting IC memory cards.

FIG. 1 is a figure illustrating the insulation structure in accordancewith a first embodiment of the invention, and shows a cross-sectionalview of a PC card. The PC card is formed from a housing structure. InFIG. 1, reference numeral 1 denotes a connector. The connector 1 isprovided with a plurality of terminals that are brought into contactwith and connected with a connector provided at an external apparatusequipped with a card drive, wherein the connector serves as a datatransmission/reception section of the external apparatus. The externalapparatus is, for example, a personal computer (PC) which can receivethe PC card. Reference numeral 2 denotes a metal plate having certainconductivity, and defining an outer casing. The metal plate 2 can bemade of a material such as SUS. Reference numeral 4 denotes a substratehaving wiring provided thereon. Electronic devices, such as input/outputIC5, semiconductor memory 6 and the like are mounted on the substrate toform circuits thereon. Reference numeral 3 denotes a conductive memberthat electrically connects the metal plate 2 and the substrate 4, and aspring is used therefor in this embodiment. Alternatively, a connectoror the like may be used as long as they are electrically connectable andconductive. The spring is connected to GND of the substrate, forelectrically connecting the metal plate so that it conducts with thesubstrate. Reference numeral 8 denotes a plastic frame, which covers aportion of or the entirety of the side surface of the substrate (a sidesurface on which electronic devices are not mounted), and defines anouter casing for the side surface of the PC card. Reference numeral 7denotes an electrically insulative material, such as, for example, aninsulation sheet. Here, a tape-shaped member having an adhesive layer onone surface thereof is used therefor.

In the PC card as shown in FIG. 13, the substrate 4, on which theinput/output IC 5, the semiconductor memory 6, the connector 1 and theconductive spring 3 are mounted, is disposed on the plastic frame 8. Themetal plates 2, such as SUS plates, are fixed with adhesive to bothupper and lower sides of the plastic frame 8. The metal plates and theplastic frame 8 are formed into an integral structure by applying heatand pressure. Here, one end of the spring 3 is connected to a GNDpattern formed on the substrate 4 with solder or by means ofpressure-coupling by using the spring feature thereof. The other end ofthe spring 3 is connected to the metal plate by means ofpressure-coupling. Since the substrate 4 and the metal plate 2 areelectrically conductive due to the spring 3, when a person charged withstatic electricity touches the card, the charge (static electricity)charged in the person flows to the metal plate 2, then from the metalplate 2 through the spring 3 to the GND line of the substrate 4.Further, it flows from the GND line through the connector of the PC tothe PC main body. As a result, malfunctions of the PC, such as, forexample, halt and erroneous operations of the PC occur.

Therefore, a portion of the metal plate 2 where the person touches iscovered by an insulation member, such as, the insulation tape 7 toprevent the electrostatic charge from flowing to the metal plate 2, andthus, the flow thereof to the PC apparatus body is prevented.Preferably, in accordance with the embodiment, a portion of the metalplate 2 that protrudes from the PC apparatus body when the PC card ismounted on the PC apparatus body is covered by the insulation tape 7. Itis noted that the insulation material is preferably in the shape of atape so that the provision thereof is easy and the thinness of the cardcan be maintained to some degree. For the insulation member, anymaterials, such as, for example, vinyl chloride and the like, may beused as long as they can be used as the insulation tape 7. Also, theinsulation tape 7 may be provided with a function of slip-stopper.Namely, a member having a certain degree of surface roughness may beused for the tape.

When the center line of the card in the right-to-left direction (thelength direction) of FIG. 1 is assumed to be a border of regions, it isnoted that the insulation tape 7 may cover more than half of the regionmeasured from the end side of the card, which is on the opposite side ofthe connector 1. In particular, in the case of an ordinary PC card whichis about 86 mm in dimension in the length direction of the card, aboutone third of the region on the opposite side of the connector 1 measuredfrom the end side toward the center of the card is preferably covered bythe insulation tape 7.

FIG. 2 shows a cross-sectional view of a second embodiment of theinvention. In FIG. 2, both sides of the substrate 4 on the connectorside are covered by metal plates 2. Both sides of the substrate 4 on theopposite side of the connector side 1 are covered by plastic plates 10which are insulation members that define outer casings. The plasticplates 10 are formed independently of the plastic frame 8, and are fixedto the frame 8 with adhesive in a similar manner as the metal plates 2.In this case, in a similar manner as in the above-described firstembodiment, the plastic plates 10 are provided in at least an area ofthe PC card which protrudes from the PC apparatus body when the PC cardis inserted in the PC apparatus body and, preferably, in an areacovering about one third of the length of the PC card. The plasticplates 10 are preferably formed from a polyamide resin, such as, forexample, nylon, polyphenylene sulphide (PPS) resin, acrylonitrilebutadiene styrene (ABS) resin and the like. In accordance with thesecond embodiment, the plastic plates 10 are used as insulation members,and therefore can provide better insulation than provided in the firstembodiment. Moreover, the plastic plates 10 are formed independently ofthe plastic frame 8, and the plastic frame 8 is formed from, forexample, PPS. As a result, a high degree of measurement accuracy isachieved, and the flatness and the measurement accuracy of the plasticplates 10 are also improved.

FIG. 3 shows an example of a variation of the plastic plates 10. Upperand lower plastic plates 10 a, 10 b are provided with protruded deformprevention sections 11 a, 11 b formed on internal surfaces of the platesin areas corresponding to locations which are grabbed and held by thehand of a person. Also, the substrate 4 defines a through-hole in anarea corresponding to the deform prevention sections 11 a, 11 b to allowthe deform prevention sections 11 a, 11 b to pass therethrough. Thedeform prevention section 11 a formed on the upper plastic plate 10 a isformed, for example, in the shape of a truncated cone. The deformprevention section 11 b formed on the lower plastic plate 10 b definesan opening that receives the deform prevention section 11 a. Thisstructure prevents the plastic plates 10 a, 10 b from bending anddeforming when the PC card is inserted or withdrawn. Furthermore, sincethe deform prevention sections 11 a and 11 b engage each other, relativepositioning of the plastic plates 10 a, 10 b is achieved. Also, sincethe deform prevention section 11 b passes through the substrate 4, itcan be used to position the substrate 4. Alternatively, the upper andlower deform prevention sections 11 a, 11 b may be formed so that theyface each other, and abut the upper and the lower surfaces of thesubstrate 4. If the deform prevention sections 11 a, 11 b are formed sothat they abut the substrate, drilling the hole in the substrate 4 isnot required, and thus the number of process steps can be reduced.

FIG. 4 shows a plastic frame in accordance with another embodiment ofthe invention. A plastic frame 8 includes step section 12 formed on aninterior edge section thereof in its top-down direction for holding themetal plate 2 and the plastic plates 10 a, 10 b. Step section 14 isfurther formed in an area internal to the step section 12 for holdingthe substrate 4. Also, the plastic frame 8 is integrally provided with abeam 16 extending between the step section 14 in the width direction ata location corresponding to a border section between the metal plates 2and the plastic plates 10. By this structure, the rigidity of theplastic frame 8 is improved, and the measurement accuracy is improved.

FIG. 5 shows a third embodiment of the invention. In this embodiment,insulation members that define an outer casing and which are positionedat a location on the opposite side of the connector side are integrallyformed with the plastic frame 8. More particularly, a PC card shown inFIG. 5 has a structure in which the plastic frame 8 extends to the upperand lower surfaces of the card, namely, to the areas of the outercasing. By forming insulation outer casing sections 18 by the plasticframe 8, the card becomes stronger than the second embodiment, and isalso securely insulated. Further the number of parts and assembly stepsis reduced and thus the cost is reduced. It is noted that the plasticframe 8 can be further extended so that the plastic material is providedover the upper and lower surfaces of the card to make the entire upperand lower surfaces of the card as an outer casing.

FIG. 6 shows an example of a variation of the third embodiment. A PCcard shown in FIG. 6 has a solid section formed in about one third ofthe plastic frame 8 on the opposite side of the connector 1. Metalplates 2 are disposed on both sides of the connector 1. The metal plates2 may be fixed to the plastic frame 8 with adhesive in a similar manneras the other embodiments, pressure-inserted in the plastic frame 8 orfixed by caulking. In this embodiment, since the area of the PC cardwhich is grabbed and held is solid, the card is prevented from beingdeformed when it is inserted or withdrawn from the PC apparatus body.

FIG. 7 shows an exploded perspective view of the main portion of afourth embodiment of the invention. In this embodiment, a plastic frame8 is formed from an upper frame member 8 a and a lower frame member 8 b.Each of the frame members 8 a, 8 b is integrally formed with aninsulative outer casing section 18, and formed in a single piece with ametal plate 2 when each of the frame members 8 a, 8 b is molded.Further, a step section 20 is provided in the inner periphery of thelower frame member 8 b for disposing a substrate. The upper and lowerframe members 8 a, 8 b can be joined by means of adhesive, ultrasoundwelding and the like. In this embodiment, the frame, metal plates andthe insulative outer casing section 18 are formed in a single piece, sothat the assembly of the card is readily performed.

In a fifth embodiment of the invention shown in FIG. 8, when framemembers 8 a, 8 b are molded, they are integrally formed with metalplates 2, in a manner similar to the fourth embodiment shown in FIG. 7.In this embodiment, outer casing section 18 externally protrudes and hasa U-shape cross-section. By forming the insulative outer casing section18 in a U-shape cross-section, the plate thickness of the plasticmaterial, which has a smaller rigidity compared with a metal, can bemade greater to increase the strength (rigidity) of the insulative outercasing section 18. Accordingly, a space for mounting parts is formedinside the insulative outer casing section 18, and therefore a largesubstrate 4 can be used.

FIG. 9 shows an exploded perspective view of a sixth embodiment of theinvention. As shown in the figure, a plastic frame section 8 is formedfrom a frame member 8 c on the side of the connector, and upper framemember 8 d and lower frame member 8 e which define a section on theopposite side of the connector. Each of the upper and lower framemembers 8 d, 8 e, is formed from an integrated piece of a frame section20, an insulative outer casing section 22 and a metal plate 2. Metalplates 2 are disposed in a manner such that they cover substantially theentire region of the plastic frame section 8. In other words, both theentire surfaces of the substrate 4, and the insulative outer casingsection 22 cover a part of the external surfaces of the metal plates 2.In the fifth embodiment, the metal plates 2 are entirely disposed overboth of the surfaces of the card, and therefore the strength of the cardis increased.

FIG. 10 shows a seventh embodiment of the invention.

In FIG. 10, reference numeral 9 denotes a slip-stopper that is providedon a plastic frame 8 which is insulative. Other structures are the sameas those described above in each of the embodiments. The slip-stopper 9is integrally formed in the center of the insulative outer casingsection 18 which is integrally formed with the plastic frame 8.Moreover, the slip-stopper 9 is set to a height which is about the sameas the height of other areas of the outer casing, and therefore thethickness of the card is maintained unchanged. Because the slip-stopper9 is provided, for example, the card is readily grasped by the person'sfingers when the card is inserted or withdrawn. Accordingly, theoperability upon card insertion and withdrawal is improved.

FIG. 11 and FIG. 12 respectively show a perspective view and across-sectional view of an eighth embodiment of the invention.

A card-shaped electronic apparatus in accordance with this embodiment isa type which does not have a connector. As shown in FIG. 11, a pluralityof terminals 26 are formed on the surface of a substrate 4 by means ofplating. These terminals 26 are externally exposed so that they cancontact with contacts of a connector of an external apparatus, such as aPC, when the side of the terminals is inserted in the connector thereof.

The periphery of the substrate 4 is encircled by a plastic frame 8.Also, as shown in FIG. 12, the card has metal plates 2 disposed overabout two thirds of both surfaces of the substrate 4 on the side of theterminals. However, the upper metal plate 2 shown in FIG. 12 is disposedthereover except in an area where the terminals 26 are. The upper metalplate 2 is fixed to the substrate 4 with adhesive 24. Both sides ofabout one third of each of the terminal side region and the oppositeside region of the substrate 4 are covered by plastic plates 10.

In this embodiment, even though portions of the plastic plates 10 aregripped and held, electric charge of a person is prevented from flowingto the apparatus, and malfunctions of the apparatus are prevented.

The card without a connector shown in FIGS. 11 and 12 can be implementedin a variety of embodiments, in a similar manner as the above-describedcard with a connector.

As described above, card-shaped electronic apparatuses in accordancewith the invention are useful for I/O cards, such as, for example, ICmemory cards, fax/modem expansion boards, card-shaped hard discs and thelike that can be removably mounted on personal computers (PCs).

What is claimed is:
 1. A card-shaped electronic apparatus for use withan external apparatus having a data transmission and reception section,comprising: a substrate having electronic devices mounted thereon, aterminal end section and a through-hole; at least one terminal disposedon the terminal end section of the substrate and to contact the datatransmission and reception section of said external apparatus toestablish electrical connection between card-shaped electronic apparatusand the external apparatus; a frame positioned at the periphery of thesubstrate; upper and lower metal members respectively connected to topand bottom surfaces of the frame and cover at least apart of thesubstrate at a side of the terminal end section to define an outercasing section; and upper and lower insulation members each disposed oneach side of the substrate, and respectively connected to the upper andlower metal members, and a deform prevention section includes first andsecond members, each protruding from an inner surface of the upper andlower insulation members, the first member is passable through thethrough-hole of the substrate to engage the second member.
 2. Thecard-shaped electronic apparatus according to claim 1, wherein the upperand lower insulation members are disposed at a location that protrudesfrom the external apparatus when mounted on the external apparatus. 3.The card-shaped electronic apparatus according to claim 2, wherein theupper and lower insulation members are formed in a U-shapecross-section.
 4. The card-shaped electronic apparatus according toclaim 1, wherein the upper and lower insulation members are formed froma synthetic resin material.
 5. The card-shaped electronic apparatusaccording to claim 1, wherein at least one of the upper and lowerinsulation members is provided with a slip-stopper.
 6. The card-shapedelectronic apparatus according to claim 1, wherein the first and secondmembers of the deform prevention section abut surfaces of the substrate.7. A card-shaped electronic apparatus according to claim 1, furthercomprising a conductor member having two springs, one spring thatconnects the upper metal member to the substrate and another spring thatconnects the lower metal member to the substrate.
 8. The card shapedelectronic apparatus according to claim 1, wherein the upper insulationmember and the lower insulation member are jointless.